In patients with heart failure with preserved ejection fraction (HFpEF), atrial fibrillation (AF) is associated with peak exercise intolerance, impaired contractile reserve, and increased mortality, but not submaximal exercise capacity, a recent study found. 1,744 patients with HF and ejection fraction and referred for cardiopulmonary stress testing were included in the analysis, 239 of whom had AF. A weighted linear regression model was used to compare metabolic stress parameters and 8-year total mortality between both groups. Researchers found:

• Weighed mean ejection fraction was 58±5.9% in the entire population.
• Patients with AF vs those without AF had lower mean peak oxygen consumption, oxygen pulse, and circulatory power, but similar submaximal exercise capacity, after adjusting for unbalanced weighted variables.
• Both groups had similar peak heart rate, while mean peak systolic blood pressure was lower in the AF group.
• AF was associated with higher total mortality.